Cook the couscous according to packet instructions, and allow it to cool in a large bowl.
Break off any woody ends of the asparagus and diagonally slice spears into 2cm pieces. Blanch for about a minute, then cool and drain.
Tear salad greens into even pieces. Cut the snow peas into halves or thirds. Rinse and drain the four-bean mix. Finely slice the spring onions.
Add all these ingredients to the large bowl. In a small bowl, peel the ginger root and finely grate it into the citrus juice. Whisk in the sugar until dissolved. Pour dressing over the salad, toss, and serve.
Very good as a bed for falafel or other bean patties.